Safety enclosure for off-shore oil rigs

ABSTRACT

The floatable safety enclosure is formed by a plurality of upwardly extending, floatable wall sections which are adapted to be floated into position around an off-shore oil or gas well platform and secured together to form a continuous, dome-like wall around the platform.

451 May 1, 1973 United States Patent [1 1 Roy SAFETY ENCLOSURE FOR OFF-SHORE OIL RIGS [761' Inventor:

3.664.429 5/1972 Jonesmm. ...169/2R 3,685,584 8/1972 Lawrence F. Roy, 27Rambler Road, Southampton, Pa. 18966 Primary Examiner-Allen N. KnowlesAssistant ExaminerMichael Mar Attorney-Bacon and Thomas 22 Filed: Feb.17, 1972 211 App]. No.: 227,053

[57] ABSTRACT The floatable safety enclosure is formed by a plurality ofupwardly extending, floatable wall sections which are adapted to befloated into position around an offshore oil or gas well platform andsecured together to form a continuous, dome-like wall around theplatform.

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16 Claims, 6 Drawing Figures [5 6] References Cited UNITED STATESPATENTS Verdin Paremgd Ma '1, 1973 v 3,730,213

3 Sheets-Sheet 1 Patented May 1, 1973 5 Sheets-Sheet 2 Patghted May 1,1973 v 3,730,278

5 Sheets-Sheet 5 mosphere and water in the vicinity, but also needlesslywasting natural resources.

BRIEF SUMMARY OF THE INVENTION The floatable safety enclosure of thisinvention obviates many of the difficulties and disadvantages previouslyencountered in extinguishing gas and oil well offshore fires andprovides an enclosure or dome for enclosing an off-shore platform or rigwith a continuous wall which extends above the top of the rig asubstantial distance so that a fire within the enclosure is quicklysmothered.

It is an object of this invention to provide a floatable safety deviceor enclosure for off-shore gas or oil well platforms which will preventcombustion supporting air outside of the enclosure from reaching a firewithin the enclosure.

Another object of the invention is to provide a safety enclosure whichmay be floated into position around an off-shore platform.

A further object of the invention is to provide an enclosure formed of aplurality of parts which may be floated into position around anoff-shore platform and then secured together to provide a continuouswall or dome around the platform.

It is also an object of the invention to provide an enclosure foroffshore oil rigs which will deny combustion supporting air to a firewithin the enclosure and will confine oil escaping from uncontrolledwells discharging within the enclosure.

These and other objects and advantages of the invention will become moreapparent from a following specification and claims when taken inconjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS showing the cooperative ends of theballast chambers spaced apart;

FIG. 5 is a top plan view of a second form of the floatable safetyenclosure; and

FIG. 6 is an elevation view of the enclosure of FIG. 5.

2 7 DETAILED DESCRIPTION or THE DRAWINGS The form of the invention shownin FIGS. 1-4 comprises an enclosure, formed of two floatable sectionsdesignated generally A and B, which provides a continuous wall around anoil or gas off-shore platform designated generally by the referencecharacter C.

The enclosure is of generally circular configuration in plan view and isof generally frusto-conical configuration in transverse section. Sincethe sections A and B are similar in structure, only section A will bedescribed in detail.

Section A of the floatable safety enclosure includes a lower portion 3of generally hemicycle configuration which extends upwardly from ahollow float or ballast chamber 5 and converges inwardly toward theoffshore drilling rig platform C. As seen in cross section in F IG. 2,the lower wall portion 3 appears to be of generally frusto-conicalconfiguration.

The upper wall portion 7 extends upwardly from the upper edge 9 of thelower wall portion 3 and converges inwardly at a greater angle to thevertical than does the lower wall portion 3. The upper wall portion isalso of generally frusto-conical configuration as viewed in crosssection in FIG. 2 and the portion of the wall which extends around andis adjacent to the top opening 11 formed in the upper wall portion 7 iscurved and is directed downwardly and converges inwardly of the openingto provide a curved deflector portion 13 on the inner surface of theupper wall portion 7. v

The lower edge 15 of the lower wall portion 3 is semi-circular and ismounted on the upper surface of the float or ballast chamber 5 which isalso ofsemi-circular configuration. I

The float or ballast chamber 5 includes a top wall 17 on which the lowerwall portion 3 is mounted, a bottom wall 19, an inner wall 21, and anouter wall 23. The ballast chamber also includes the walls 24 and 25 ateither end thereof which complete the ballast chamber 5 and make it airand water tight.

A plurality of rigid feet 26 are fixedly secured to the bottom wall 19at spaced intervals along the bottom wall from one end to the other endthereof and are adapted to engage the ground for supporting the ballastchamber 5 and the remainder of the section A above the surface of theground. If desired, instead ofa plurality of feet 25, a single,continuous, arcuate foot could be attached to the bottom wall 19 andextend from adjacent one end to adjacent the other end of the ballastchamber.

The ballast chamber 5, which is preferably formed of heavy sheet metalwelded together to form a water tight float, is of sufficient size andstrength to support the wall portions 3 and 5 in a generally verticalposition above the surface of the water. The ballast chamber may bepartially filled with water or additional solid ballast may'be added tothe chamber as found necessary.

The outer surface 27 of the lower wall portion 3 and the outer surface29 of the upper wall portion 7 is preferably formed of heavy sheet metaland both the lower and the upper wall portions 3 and 7 are provided witha lining of a suitable fire resistant material 31 such as asbestos or aceramic.

Heavy, metal gusset plates 33 are welded or otherwise fixedly secured tothe top wall 17 of the ballast 3 chamber 5 and to the outer surface 27of the lower wall portion 3 in order to maintain the wall of section Ain an upright position.

A walkway or catwalk 35 extends around the outer periphery of the lowerwall portion 3 and is supported above the top wall 17 of the ballastchamber 5 by suitable support members 37. Suitable ladders, not shown,extend from the platform 35 to the top wall 17 of the ballast chamberand a fire-proof closure 39 is mounted in the lower wall portion 3 sothat access to the interior of the enclosure may be had from theplatform 35.

The ballast chamber 5 carries one or more reversible pumps 41 which areadapted to pump ballast water from the outside of the enclosure into theballast chamber 5 through a conduit 43 or to pump the ballast water outof the ballast chamber through the conduit 43. A plurality of floodports 44 controlled by valves 44a permit water from outside the chamber5 to flow into the chamber when the valves are open. In this manner, thefloating section may be lowered or raised in the water. Electric powergenerating means, not shown, is carried by the section A for supplyingthe electric power required to operate pumps or other machinery carriedby the section.

in order to cool the walls of the section A of the enclosure, a curvedspray head or pipe 45 provided with suitable spray orifices 47, isfixedly secured adjacent the top edge of the outer surface 29 of theupper wall portion 7. Water under pressure is adapted to be supplied tothe spray head 45 from outside of the enclosure through a conduit 49 andpump 51. The pumps 41 and 51 may be mounted on the top wall 17 of theballast chamber 5 and controls 52 for these two pumps may be suitablylocated on the walkway 35.

The sections A and B, after being floated into position around anoff-shore gas or oil rig, are adapted to be secured together to providea continuous wall or dome around the off-shore well platform. Indescribing section B, the reference numerals employed in describingsection A, will be used followed by an a to designate like parts. s

The end wall 24 of the ballast chamber 5 of section A and the adjacentend wall 25a of the ballast chamber section B, as best shown FIGS. 1, 3,and 4, are provided with cooperating tongue and groove structure forsecuring the section A and B together with the ballast chambers 5 and 5ain substantially vertical and horizontal alignment and with thegenerally vertically extending side edge portions of the lower and upperwall portions of sections A and B contiguous.

The end wall 24 of section A is formed with a vertically extending,tapered groove 53 while the end wall 25 of section A is formed with atapered tongue 55. In like manner, the end wall 25a of the ballastchamber 5a of section B is provided with a tongue 55a which cooperateswith the groove 53 of section A while the other end of the ballastchamber 5a of section B is provided with a groove 53a into which thetongue 55 of section A extends.

As shown in FIG. 4, the groove 53 of section A includes a pair of sidewalls 57 and 59 which converge inwardly from the end wall 24 to an innerend wall 61 while the tongue 55a of section B includes the side walls63a and 65a which extend outwardly from the end wall 25a and converge toan outer end wall 67a.

A ledge 69a is positioned below the tongue 55a at one end of the ballastchamber 5a of section B and extends outwardly and upwardly to provide amale bottom rest which is adapted to be seated in a socket 71 formedin'one end of the ballast chamber 5 of section A. The ledge 69a andsocket 71 cooperate-to assist in maintaining the' sections A and B invertical alignment while the tongue 55a and groove 53 hold the sectionsin horizontal alignment. The other end of the ballast chamber 5 ofsection A is provided with a ledge similar to the ledge 69a of section Bwhile the other end of the ballast chamber 5a is provided with a socketsimilar to the socket 71 of section A.

The side edge portions of the walls 3 and 7 are provided with sealingmembers 73 which cooperate with the adjacent side edge portions of thewalls of section and form a tight joint between the walls of sections Aand B for preventing the air outside of the enclosure for entering theinterior thereof between the side edges of the side walls of the dome.

The cooperating ends of the ballast chambers 5 and 5a are drawn togetherby means of power driven winches 75 and 75a mounted on the top wall ofballast chambers 5 and 5a. As best shown in FIG. 4, the winch 75a fixedon ballast chamber 5a includes a rotatable drum 77a on which a steelcable 79a is wound. The free end of the cable 79a carries a hook 81aadapted to be detachably connected to an l-bolt 83 fixedto the lowerportion of the adjacent gusset plate 33 carried by ballast chamber 5.

After the cooperating ends of the sections A and B are drawn intoproximity by the winches 75 and 75a, hydraulic chain jacks 85 and 85aare employed for holding the cooperating ends of the ballast chambers inengagement with the tongues 55 and 55a seated in the grooves 53 and 53a.The chains 87 and 87a carried by the hydraulic chain jacks 85 and 85aare connected to v upstanding hooks 89 and 89a carried by the top wallof the ballast chamber of the adjacent section.

After the sections A and B are moved into position around an off-shoreplatform and attached together by the chains 87 a 7a, the ballastchambers 5 and 5a form a continuous enclosure which will serve toconfine any pumped into a barge or other storage vessel by means of apump 91 connected with a conduit 93 which extends through the lower wallportion 3 and then downwardly into the liquid confined within theenclosure.

A fire within the enclosure would be extinguished as soon as the oxygenin the air within the enclosure was consumed. Since the ballast chambersand the lower and upper wall portions of the sections completely enclosethe rig, and hot gases of combustion would flow outwardly through therelatively small top opening 11, air for supporting combustion could notenter the enclosure and therefore the tire would be quickly extinguishedfor lack of oxygen.

. the top opening above the enclosed platform.

The sections A and B are each provided with means to anchor them inposition, not shown, and each section would carry a supply of varioustypes of fire fighting chemicals as well as the tools and equipmentnecessary to repair a well and its platform after a fire has beenextinguished.

While the enclosure is illustrated and described as being formed of twosections A and B, it could obviously be formed of more than twosections. The dimensions of the sections of the enclosure are determinedto some extent by the number of well heads connected with an off-shoreplatform and with the size and height of the rig.

' A great advantage of the floatable safety enclosure is a thatthehsections can be moved into position close to a burning off-shore rigor platform by being pushed by a tug or like vessel. The tub would beprotected from the fire by the wall of the section which wouldconstitute a barrier or heat shield for the tug.

The concept of this invention includes a floatable safety enclosure ofany suitable configuration, such as for example triangular or squareformed of a plurality of sections secured together in abuttingrelationship so as to trap oil within the enclosure and to provide acontinuous wall around an shore platform for preventing combustionsupporting air from reaching a firewithin the enclosure.

In the form of the invention illustrated in FIGS. 5 and i 6, the safetyenclosure is of generally square configuration and is formed by a pairof similar sections 102 and 104. Section 102 includes verticallyextending walls 106, 108, and 110 fixedly mounted on a water and airtight ballast chamber 112 which may be flooded with water or pumped outin a manner similar to that already described in connection with theform of the invention shown in FIGS. 1-4.

Support blocks or feet 114 for engaging the ground and the section arefixed to the lower surface of the ballast chamber 112, and a walkway 116extends around the outside of the walls 106, 108, and 110 a shortdistance above the upper surface of the ballast chamber 112.

The section 112 includes a top wall 118 which abuts against the top wall120 of the section 104. A semi-circular opening 126, formed in the edgeof the top wall 118 midway between the opposite ends of the edge of thewall, cooperates with a semi-circular opening 128 formed in the edge ofthe top wall 120, to form a circular opening 130 when the section 102and 104 are secured together.

In order to assist in bringing the sections 102 and 104 into alignment,an aligning tongue 122 is provided on the edge of the top wall 118 atone side of the circular opening 130 and a cooperating recess 124 isformed in the edge of the top wall 120 for receiving the tongue 122. Alike arrangement is provided on the other side of the circular openingwhere an aligning tongue 132 is formed on the edge of the top wall 120and a cooperating recess 134 is formedin the edge of the top wall 118 toreceive the aligning; tongue 132. The sections 102 and 104 may befurther maintained in alignment and secured together by providing theballast chambers of the sections with alignment and securing meanssimilar to those shown in FIGS. l-4 and employed in connection with theform of the invention previously described. In like manner, the walls ofthe sections 102 may be line with fire resistant material and the wallsmay be cooled by spraying water on the outer surface thereof. A ladder136 extends from the walkway 116 to the top of section 102. i

A closure 138 provided for the circular opening 130, is pivotallymounted at 140 on the top wall 118 and is adapted to be moved fromtheclosed position shown in solid lines to the open position shown inbroken lines by a hydraulic motor 142. The cylinder of the hydraulicmotor 142 is pivoted at 144 to the upper wall 118 of section 102 a heprojecting end of the piston rod 146 is pivoted at 148 to the closure138. By actuating the hydraulic motor 142, the closure 138 may be movedto selectively cover or uncover the circular opening 130.

The floatable safety enclosure shown in FIGS. 5 and 6 is similar to theone previously described and is adapted to extinguish fires within theenclosure by preventing combustion supporting air from reaching theinterior of the enclosure. Oil. escaping from a well within theenclosure is trapped and confined by the ballast chambers and may bepumped out of the enclosure to a barge or storage facilityin a mannersimilar to that described above. I

While preferred forms of the invention have been described and disclosedherein, such changes and modifications as may occurred to those skilledin the art are to be considered within the perview of this invention asfall within the scope of the apended claims.

What I claim is:

l. A floatable safety enclosure for off-shore oil rigs, comprising: awall of fire resistant material completely surrounding an off-shore oilrig and extending from the surface of the water upwardly to a heightsubstantially above the upper end of the rig, said wall comprising aplurality of upwardly extending adjacent sections each having generallyvertically extending, side edge portions; float means rigid with thelower edge portion of each section of the wall and extending along thelength thereof for supporting the wall sections in a generally verticalattitude above the surface of the water; and means for detachablysecuring adjacent sections together with the side edge portions ofadjacent sections in abutment whereby said sections form a continuouswall around the oil rig. t

2. A floatable safety enclosure according to claim 1 in which the wallsof the sections converge upwardly and the upper edge portions of thewall sections form a top opening over the rig, the distance around the vperiphery of the top opening being substantially less than the distancearound the periphery of the lower edge of the wall. a

3. A floatable safety enclosure according to claim 2 in which the wallformed by said sections is of generally frusto-ccnical shape andincludes upper and lower enclosure back into the interior thereof.

5. A floatable safety enclosure according to claim 2 which includesmeans carried by said enclosure for discharging fire extinguishingsubstance into the interior of said enclosure through said top opening.

6. A floatable safety enclosure according to claim 5 in which said meansfor discharging the tire extinguishing substance comprises, spraydischarge means positioned around the periphery of the top opening andpump means operably connected with said spray discharge means and with asource of said substance.

7. A floatable safety enclosure according to claim 1 in which theupwardly extending walls of each section are generally planar, and theenclosure includes a top wall of fire resistant material which extendsinwardly over the oil rig from the planar walls of said sections.

8. A floatable safety enclosure according to claim 7 in which said topwall is provided with an opening, a

closure for said opening is movably mounted on said top wall, and poweroperated means is operably connected with said closure for moving itbetween a position covering said opening and a position remote from saidopening.

9. A floatable safety enclosure according to claim 7 in which a portionof said top wall extends inwardly from each of said sections with thefree edges thereof in abutment, and opposed, cooperating, aligning meansis provided on the free edge of the inwardly extending top portion ofsaid sections.

10. A floatable safety enclosure according to claim 1 in which the sideedge portions of the floats of adjacent sections are in abutment whenthe sections are attached together, and the opposed edge portions ofadjacent floats have cooperating means carried thereby for bringingadjacent floats and the sections carried thereby into alignment.

11. A floatable safety enclosure according toclaim 10 in which thecooperating means carried by adjacent floats comprises a tongue carriedby one float seated with a close sliding fit in a cooperating recessformed in the opposed edge portion of the adjacent float.

12. A floatable safety enclosure according to claim 10 in which themeans for detachably securing adjacent sections together includes asubstantially non-extensible, flexible strand fixedly connected at oneend to one float, and power operated pulling means mounted on the otherfloat and connected to the other end of the strand for pulling theopposed edge portions of the floats and the cooperating means carriedthereby into abutment.

13. A floatable safety enclosure according to claim 1 in which each ofsaid float means comprises a tank providing a water ballast chamber,valve means for controlling the flow of water into the ballast chamber,and pump means for removing water from the ballast chamber.

14. A floatable safety enclosure according to claim 13 in which eachtank carries foot means engage'able with the ground for supporting theballast chamber above the surface of the ground.

15. A floatable safety enclosure according to claim 13 in which at leastone of the tanks includes conduit means connecting the interior of theenclosure with the exterior thereof and oil pump means connected withsaid conduit means for pumping oil on the surface of the water withinthe enclosure to the exterior thereof.

16. A floatable safety enclosure according to claim 13 in which each ofthe sections includes pipe means having outlet means for dischargingwater over the exterior of the section and inlet means disposed in thewater adjacent the enclosure and water pump means operably connectedwith said pipe means for pumping water therethrough.

1. A floatable safety enclosure for off-shore oil rigs, comprising: awall of fire resistant material completely surrounding an off-shore oilrig and extending from the surface of the water upwardly to a heightsubstantially above the upper end of the rig, said wall comprising aplurality of upwardly extending adjacent sections each having generallyvertically extending, side edge portions; float means rigid with thelower edge portion of each section of the wall and extending along thelength thereof for supporting the wall sections in a generally verticalattitude above the surface of the water; and means for detachablysecuring adjacent sections together with the side edge portions ofadjacent sections in abutment whereby said sections form a continuouswall around the oil rig.
 2. A floatable safety enclosure according toclaim 1 in which the walls of the sections converGe upwardly and theupper edge portions of the wall sections form a top opening over therig, the distance around the periphery of the top opening beingsubstantially less than the distance around the periphery of the loweredge of the wall.
 3. A floatable safety enclosure according to claim 2in which the wall formed by said sections is of generally frusto-conicalshape and includes upper and lower frusto-conical portion, the upperfrusto-conical portion extending upwardly from the upper edge of thelower frusto-conical portion, the wall of the upper frusto-conicalportion converging upwardly at a greater angle to the vertical than thewall of the lower frusto-conical portion.
 4. A floatable safetyenclosure according to claim 2 in which the portion of the wallextending around and adjacent to the top opening is directed downwardlyand converges inwardly of the opening providing a curved deflector fordirecting smoke and flame rising with the enclosure back into theinterior thereof.
 5. A floatable safety enclosure according to claim 2which includes means carried by said enclosure for discharging fireextinguishing substance into the interior of said enclosure through saidtop opening.
 6. A floatable safety enclosure according to claim 5 inwhich said means for discharging the fire extinguishing substancecomprises, spray discharge means positioned around the periphery of thetop opening and pump means operably connected with said spray dischargemeans and with a source of said substance.
 7. A floatable safetyenclosure according to claim 1 in which the upwardly extending walls ofeach section are generally planar, and the enclosure includes a top wallof fire resistant material which extends inwardly over the oil rig fromthe planar walls of said sections.
 8. A floatable safety enclosureaccording to claim 7 in which said top wall is provided with an opening,a closure for said opening is movably mounted on said top wall, andpower operated means is operably connected with said closure for movingit between a position covering said opening and a position remote fromsaid opening.
 9. A floatable safety enclosure according to claim 7 inwhich a portion of said top wall extends inwardly from each of saidsections with the free edges thereof in abutment, and opposed,cooperating, aligning means is provided on the free edge of the inwardlyextending top portion of said sections.
 10. A floatable safety enclosureaccording to claim 1 in which the side edge portions of the floats ofadjacent sections are in abutment when the sections are attachedtogether, and the opposed edge portions of adjacent floats havecooperating means carried thereby for bringing adjacent floats and thesections carried thereby into alignment.
 11. A floatable safetyenclosure according to claim 10 in which the cooperating means carriedby adjacent floats comprises a tongue carried by one float seated with aclose sliding fit in a cooperating recess formed in the opposed edgeportion of the adjacent float.
 12. A floatable safety enclosureaccording to claim 10 in which the means for detachably securingadjacent sections together includes a substantially non-extensible,flexible strand fixedly connected at one end to one float, and poweroperated pulling means mounted on the other float and connected to theother end of the strand for pulling the opposed edge portions of thefloats and the cooperating means carried thereby into abutment.
 13. Afloatable safety enclosure according to claim 1 in which each of saidfloat means comprises a tank providing a water ballast chamber, valvemeans for controlling the flow of water into the ballast chamber, andpump means for removing water from the ballast chamber.
 14. A floatablesafety enclosure according to claim 13 in which each tank carries footmeans engageable with the ground for supporting the ballast chamberabove the surface of the ground.
 15. A floatable safety enclosureaccording to claim 13 in which at least One of the tanks includesconduit means connecting the interior of the enclosure with the exteriorthereof and oil pump means connected with said conduit means for pumpingoil on the surface of the water within the enclosure to the exteriorthereof.
 16. A floatable safety enclosure according to claim 13 in whicheach of the sections includes pipe means having outlet means fordischarging water over the exterior of the section and inlet meansdisposed in the water adjacent the enclosure and water pump meansoperably connected with said pipe means for pumping water therethrough.